Tom" wrote in message
...
Sorry for the fuss here tonight. I have settled on the Dobs, rather than
the
adventure into Apochromats. It's the money.

Nobody has said why the Orion XT10 is worth 50 bucks more, and the
Hardin comes with Messier list and a moon filter if I remember correctly.
I'll go with the Hardin I guess. There is a barlow lense offered for 50
bucks
as an accessory. I assume this scope can handle a 300x magnification, but
the
barlow is achromatic. Would an achromatic barlow cause chromatic
aberation
in a newtonian scope?

Also, there is the laser collimator. I read some literature here on star
testing, so
does this make the laser obsolete? And one more thing, bear with me
here....
is correcting the optics just a harmless excersise in trial and
error...lighly tweaking
the screws? I have read how to tell if something is wrong, and even what
is
wrong, but not much on which screws to tweak. -Thanks.
Tom



Congratulations on your Dob -- you'll enjoy it -- if you don't know the sky
very well (as I do not) you'll find yourself frustrated now and then by not
being able to immediately find what you are looking for but keep looking --
it's out there.

As someone else pointed out, you need to check into the spider/secondary
holder -- the Orion spider/secondary holder is steel and adjustable; the
Hardin may be plastic -- steel is better, much better.

Collimation: Forget the laser collimator. Use the collimating cap that
comes with the scope. Then, look around for a set of collimating tools made
by Tectron. You will also need a #2 Phillips screwdriver and a hex key to
fit the tiny hex head screws that adjust the tilt of the secondary.

Here is my experience with collimating my XT-8; hope you find something
useful here.
http://www.schlatter.org/Dad/Astronomy/collimate.htm

When you can, get a right-angle finder scope and a Telrad. Check it out
he
http://www.schlatter.org/Dad/Astronomy/xt%208.htm

Get some books and a planisphe
http://www.schlatter.org/Dad/Astronomy/books.htm

And you thought the telescope was expensive!!!

Also, get some clear skies without pollution from a nearby WalMart parking
lot.

---------------
Joe S.